Fully differential non-inverted parallel amplifier for detecting biology electrical signal

Abstract

This invention relates to a fully differential non-inverting parallel amplifier for detecting biology electrical signal, including input buffer circuits, differential filter circuits, data selector, non-inverting parallel amplifying circuits and analog-digital circuits. The biology electrical signal, first impeded and converted by the input buffer circuits, and then low-pass filtered by the differential filter circuits, shall be amplified with its common mode signal rejected by passing through the data selector and non-inverting parallel amplifier circuits. At last, the amplified biology electrical signal is output by analog to digital conversion in the analog-digital circuits after its noises beyond signal high frequency band are filtered by anti-aliasing filter net. This invention, with low noise and high common mode rejection ratio, stable baseline, large signal input dynamic range, is reliable and not easy to be saturated. Furthermore, it can support mature PACE Detecting with a low cost. It is notable in social and economical benefits for its simple electrical circuits and easy use in any biology electrical testing equipments and controlling system.

What is claimed is: 
     
       1. A fully differential non-inverting parallel amplifier for detecting biology electrical signal, characterized in that it includes input buffer circuits, differential filter circuits, data selector, non-inverting parallel amplifying circuits and analog-digital circuits; wherein the biology electrical signal, first impeded and converted by the input buffer circuits, and then low-pass filtered by the differential filter circuits, shall be amplified with its common mode signal rejected by passing through the data selector and non-inverting parallel amplifier circuits; then, the amplified biology electrical signal is output by analog to digital conversion in the analog-digital circuits after its noises beyond signal high frequency band are filtered by anti-aliasing filter net. 
     
     
       2. A fully differential non-inverting parallel amplifier for detecting biology electrical signal as set forth in  claim 1 , characterized in that the foresaid input buffer has nine circuits U 1 ˜U 9 ; each circuits is comprised by one low-noise single operational amplifier which is connected like voltage follower; and its non-inverting input is connected with the circuits current limiting resistance while the inverting input is connected with output end and the input end of differential filtering circuits. 
     
     
       3. A fully differential non-inverting parallel amplifier for detecting biology electrical signal as set forth in  claim 1 , characterized in that the differential filtering circuits has eight circuits; each circuits has first order differential low pass filter comprised by two resistances and one capacitor; one end of the resistance is connected with the output end of buffer circuits while the other is connected with capacitor filter and data selector input as well; and both ends of the capacitor filter are connected with resistance filter separately. 
     
     
       4. A fully differential non-inverting parallel amplifier for detecting biology electrical signal as set forth in  claim 1 , characterized in that the foresaid data selector is an analog switch of analog-digital converter internal integration with high resolution which can be equipped as one choosing from eight differential input and output, and 8 differential input ends shall be connected with conductor I and II and the outputs of differential filter V 1 -V 6 . 
     
     
       5. A fully differential non-inverting parallel amplifier for detecting biology electrical signal as set forth in  claim 1 , characterized in that the foresaid differential non-inverting parallel amplifying circuits is one circuits; the circuits mainly includes double operational amplifier U 10 , U 11 , resistance R 19 -R 23  and capacitor C 9 ; wherein the non-inverting end of U 10  is connected with the normal phase output MUXP of U 12 ; the non-inverting end of U 11  is connected with the negative output MUXN of U 12 ; the inverting end of U 10  and U 11  is connected with resistance R 19 ; the inverting end of U 10  and U 11  are connected with output of U 10  and U 11  through R 20  and R 21  separately; the output of U 10  and U 11  are connected with one end of R 22  and R 23  in filtering net, while the other end of R 22  and R 23  are connected with capacitor filter C 9  and the positive input IN+ and negative input IN− of analog-digital converter at the same time. 
     
     
       6. A fully differential non-inverting parallel amplifier for detecting biology electrical signal as set forth in  claim 5 , characterized in that the IN+ and IN− of analog-digital converter are connected with R 22  and R 23  separately, and the digital signal output is connected with microprocessor through SPI or LVDS.